Abstract: Owing to the most of oil and gas pipelines laid underground, it is difficult to detect pipeline centerline position, pipeline displacement and even deformation thoroughly and systematically. In order to acquire accurate coordinates of underground pipeline centerline, high precision inertial navigation units are placed into carriers for pipeline inspection according to the characteristics of the inertial navigation system. The pipeline positions are determined and modified under normal pipeline running status using inertial measurement units integrated with GPS coordinates of surface high accuracy reference points, and 3D pipeline coordinates and trends are described precisely. The test results show that the testing method can calculate pipeline centerline coordinates exactly and provide scientific basis to the prevention of pipeline accidents and pipeline maintenance, and this method is playing an important role in ensuring pipeline safety running.